There is a present demand for devices and means for converting furnaces using oil for combustion heat to ones capable of using gas. It is common in the domestic marketplace to replace a whole furnace when it is desired to convert to gas from oil as the source of fuel. There is a need for a gas burner that can be used in the combustion chamber of an oil furnace. Such a burner must be capable of creating a self controlled flame and must have fan and motor means of sufficient capacitor to create a velocity of air to maintain a stable flame.
The oil to gas conversion burners now known are fan assisted type burners. Fan assisted burners have combustion air supplied by a fan or blower of sufficient force pressure to overcome the burner resistance only and the flame produced at the burner head is of a long laminar shape. A long laminar flame cannot be properly contained in the combustion chambers of the commonly used domestic oil fired furnaces. The long flames created by the commonly used gas burners causes the heat exchangers to readily burn out in oil furnaces since they have been designed to contain the bushy flames common to oil burners.
Gas burner manufacturers have made various types of flame spreader devices for attachment to gas burner heads to maintain the gas flame within the oil furnace combustion chamber and thereby to protect the furnace heat exchangers, but it is known that the devices developed to date fail from thermal fatigue after short usage and are not therefore, acceptable in the domestic burner market.
Another disadvatage of fan assisted burners is that they will not function in an appliance that has restrictions such as baffles or revertable flues. Known burners cannot achieve the pressure required to move the combustion by-products through the appliance and at the same time maintain acceptable by-product levels. Attempts at increasing the fan capacity to meet the required pressure levels have merely resulted in creating an unstable flame.